Cranes and hoists are generally used for hanging and/or transferring various bodies in various fields. However, it is not convenient to use a conventional crane or hoist for lifting and transferring electrode plates in the electrowinning or electrolic refining of metals, since there are various problems as outlined below.
Hereinafter in this specification, the term "electrowinning" is used as including "electrolytic refining".
In the electrowinning of metals, a plurality of anodes and cathodes are alternatively arranged at predetermined intervals in an electrolytic cell. These electrodes are lifted and many of them are serviced, treated, changed or renewed before or after the operation. In the electrowinning of zinc, for instance, the cathodes are taken out of the electrolytic cell and transferred to the stripping operation for recovering electrodeposited zinc, and thereafter they are again returned to the cell. The anodes are serviced and repaired if necessary after every several runs.
As mentioned above, a crane or hoist has been used for lifting and transferring electrodes. And hanging means are used for simultaneously lifting and facilitating servicing and changing of a plurality of electrodes, said means being provided with hooks which catch and pick up electrodes. The conventional hanging means are provided with hooks spaced at constant intervals, and the distance between the hooks cannot be varied. Therefore, the electrodes are carried in the closely spaced state to the stripping station. With such small a space between the electrode plates, the scraping operation is very troublesome. It would be very advantageous if the space between the electrode plates could be widened as desired. The conventional electrode-lifting means hang only electrodes of one kind, and are not provided with insulating means. Therefore, it is impossible to simultaneously lift electrodes of the different kinds by a conventional lifting means, because short-circuiting occurs.